Abstract
Primary biliary cirrhosis (PBC) is a chronic liver disease characterized by cholestasis. Recent MRI studies have confirmed the presence of cardiac abnormalities in noncirrhotic PBC patients. However, cardiorespiratory consequences of these abnormalities have not been explored. Thoracic fluid content (TFC) is a noninvasive bioelectrical impedance measure of the electrical conductivity of the chest cavity. We explored TFC and its relationship with cardiac contractility parameters in early-stage PBC patients, compared with chronic liver disease and community controls. TFC was measured in early-stage PBC (noncirrhotic; n = 78), nonalcoholic fatty liver disease (n = 23), and primary sclerosing cholangitis (n = 18) and in a community control population (n = 78). Myocardial contractility was measured as index of contractility, acceleration index, cardiac index, stroke index, left ventricular ejection time, and left ventricular work index. We also measured total arterial compliance and the Heather Index (HI; cardiac inotropy). The PBC group had significantly lower TFC compared with controls and the chronic liver disease groups (P < 0.0001). There was an association between increasing TFC and markers of cardiac function (cardiac index, stroke index, end-diastolic index, index of contractility, and acceleration index), together with indicators of cardiac inotropy and total arterial compliance. Multivariate analysis confirmed that the only parameter that independently associated with TFC was the marker of cardiac inotropy HI (P = 0.037; β 0.5). This study has confirmed that TFC is reduced in those with PBC, that this is specific to PBC, and that it associates independently with markers of cardiac inotropy.